1631544157 has 4 divisors (see below), whose sum is σ = 1641936316. Its totient is φ = 1621152000.

The previous prime is 1631544139. The next prime is 1631544181. The reversal of 1631544157 is 7514451361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7514451361 = 1051 ⋅7149811.

It can be written as a sum of positive squares in 2 ways, for example, as 194072761 + 1437471396 = 13931^2 + 37914^2 .

It is a cyclic number.

It is not a de Polignac number, because 1631544157 - 2⁷ = 1631544029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1631544137) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5195844 + ... + 5196157.

It is an arithmetic number, because the mean of its divisors is an integer number (410484079).

Almost surely, 2^1631544157 is an apocalyptic number.

It is an amenable number.

1631544157 is a deficient number, since it is larger than the sum of its proper divisors (10392159).

1631544157 is a wasteful number, since it uses less digits than its factorization.

1631544157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10392158.

The product of its digits is 50400, while the sum is 37.

The square root of 1631544157 is about 40392.3774615954. The cubic root of 1631544157 is about 1177.2434354909.

The spelling of 1631544157 in words is "one billion, six hundred thirty-one million, five hundred forty-four thousand, one hundred fifty-seven".